Methylhydrazine → Ethyl 1,4,4-trimethyl-7-oxo-4,5,6,7-tetrahydro-1H-indazole-3-carboxylate

Participants

Reaction Steps

A solution of ethyl (3-methoxy-6,6-dimethyl-2-oxocyclohex-3-en-1-yl)(oxo)acetate from the previous step (40.2 mmol theoretically) in acetic acid (65 mL) was treated dropwise with a solution of methyl hydrazine (2.14 mL, 40.2 mmol) in acetic acid (20 mL) and allowed to stand at room temperature overnight. The mixture was then diluted with water (800 mL) and extracted with ethyl acetate (500 mL×2). The organic extracts were washed with brine, dried on Na2SO4 and evaporated to dryness. The crude material was chromatographed on silica gel eluted with dichloromethane/ethyl acetate 100:5 to obtain the pure title compound (4.8 g, 47.7% yield).

Provenance & Evidence